Really, how can two seemingly normal, sometimes loving, & relatively smart kids fight & complain so much? Because they are NORMAL! That doesn't mean I have to like it, or allow it to continue in the immense proportion that it has been happening.
My kids aren't perfect, nor do I expect perfection. What I do expect is respect, tolerance, & kindness to each other & to others as well. I also expect for them to act somewhat civilized while in public. That's not too much to ask, is it? Somedays, obviously it is!
Conflict is going to arise, disobedience is going to happen, & mean words are going to be said. Its life. We are human. And we all fall short because Adam & Eve sinned. The only thing we can do is look to God, ask forgiveness, & try better next time.